Why we are using 4-20 mA as Analog signal transmission other than 3 to 19 or 2 to 18 or 6 to 22 like wise ? What is the reason behind using 4 & 20 mA? Can anyone give proper technical reply ?

5 Answers   Air Liquide,

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Which standard is used for calibration of Control Valves ?

2 Answers  

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In oil & gas industries and petrochemical industries, there are classification of zones like zone 0, zone 1, zone 2. Is there any differences in voltages or power supply supplied for the process instruments, control instruments depending on the zones

1 Answers  

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WHAT DO YOU MEAN BY LOOP IN C.

2 Answers   Wipro,

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installation process of orifice,a question asked for confusion creation in interview by BARC 1.if orifice is tightly fitted with pipe ,it will act like venturi 2.if orifice is left hanging in between liquid it will not create the pressure difference exactly,

0 Answers   BARC,

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What is the purpose of LO overhead tank in turbines.

1 Answers   ADMA OPCO,

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Lube oil pressure transmitter local it's showing 9.8 kg/cm2 but dcs side it's showing 9.26 like that what is the reason?

3 Answers   Edac,

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what is the working principle of dis-placer type level transmitter

1 Answers   Sendan,

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WHAT IS THE CAM POSITION IN CONTROL VALVE POSITIONER ? WHY IT IS USED?

0 Answers  

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What happen if we install my pressure transmitter below the elevation of pipe in natural gas service?

0 Answers  

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how many types of thermocouple cable are? give the name of each type.

1 Answers   Fabco,

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why full bore ball valve is not used in steam applications?

1 Answers  

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